So these are the charts the Munin plugin generates.
Clock frequencies.
Voltages.
Temperature.
I changed how the voltages were collected which is why that graph doesn’t have much data on it yet, and I’ve fixed the spelling error on the temperature graph in the GitHub version of the code.
I love Munin! I’ve finally got one of the Raspberry Pi’s to be reasonably stable, so I’ve set up a munin-node on it. The standard Linux sensord stuff doesn’t run on the arm core, so I had assumed I wouldn’t be able to see any exciting temperature graphs, but I was wrong!
The Raspberry Pi Debian image includes a command called vcgencmd, which allows root to interrogate various settings and measurements. That includes the temperature, clock frequencies and voltages across various components.
So I’ve knocked up a quick plugin for Munin which gathers that stuff and graphs it. You can get it over at GitHub here. The current code looks like this (but the GitHub copy will be most up-to-date),
[sourcecode language=”bash”]
#!/bin/bash
# -*- sh -*-
: << =cut
=head1 NAME
pisense_ – Wildcard-plugin to monitor Raspberry Pi sensors (temp, volts, clock speed)
=head1 CONFIGURATION
This plugin needs to be run as root for vcgencmd to work.
[pisense_*]
user root
=head2 ENVIRONMENT VARIABLES
This plugin does not use environment variables.
=head2 WILDCARD PLUGIN
This is a wildcard plugin. To specify if you want temperature,
clock speed or volts, link this file to _volt, _temp
or _clock.
For example,
ln -s /usr/share/munin/plugins/pisense_ \
/etc/munin/plugins/pisense_clock
will monitor the clock speeds of your pi.
=head1 BUGS
None known.
=head1 NOTES
This plugin is shamelessley based on the ip_ plugin (structure).
=head1 MAGIC MARKERS
#%# family=auto
#%# capabilities=autoconf suggest
=head1 AUTHOR
Tony (tony@darkstorm.co.uk).
=head1 LICENSE
It’s yours, do with it what you like.
=cut
. $MUNIN_LIBDIR/plugins/plugin.sh
sensor=${0##*/pisense_}
if [[ "$1" == "autoconf" ]]; then
if ! /opt/vc/bin/vcgencmd firmware >/dev/null 2>/dev/null; then
echo "no (could not run /opt/vc/bin/vcgencmd as user $(whoami))"
exit 0
else
echo yes
exit 0
fi
fi
# this is flawed, vcgencmd always returns with RC 0. Needs expanding.
if [[ "$1" == "suggest" ]]; then
if /opt/vc/bin/vcgencmd measure_temp >/dev/null 2>/dev/null; then
echo temp
fi
if /opt/vc/bin/vcgencmd measure_volts >/dev/null 2>/dev/null; then
echo volt
fi
if /opt/vc/bin/vcgencmd measure_clock core >/dev/null 2>/dev/null; then
echo clock
fi
exit 0
fi
if [[ "$1" == "config" ]]; then
if [[ "$sensor" == "temp" ]]
then
echo "graph_title Raspberry Pi core temp"
echo "graph_args –base 1000"
echo "graph_vlabel dgrees Celsius"
echo "graph_category sensors"
echo "temp.label Core Temperature"
echo "temp.min 0"
fi
if [[ "$sensor" == "clock" ]]
then
echo "graph_title Raspberry Pi clock frequencies"
echo "graph_args –base 1000"
echo "graph_vlabel herz"
echo "graph_category sensors"
for clock in arm core h264 isp v3d uart pwm emmc pixel vec hdmi dpi
do
echo "clock$clock.label $clock clock Frequency"
echo "clock$clock.min 0"
echo "clock$clock.type GAUGE"
done
fi
if [[ "$sensor" == "volt" ]]
then
echo "graph_title Raspberry Pi voltages"
echo "graph_args –base 1000"
echo "graph_vlabel volts"
echo "graph_category sensors"
for volt in core sdram_c sdram_i sdram_p
do
echo "volt$volt.label $volt voltage"
echo "volt$volt.min 0"
echo "volt$volt.type GAUGE"
done
fi
exit 0
fi;
if [[ "$sensor" == "temp" ]]
then
temp=$(/opt/vc/bin/vcgencmd measure_temp | awk -F"=" ‘{print $2}’ | awk -F"’" ‘{print $1}’)
echo "temp.value $temp"
fi
if [[ "$sensor" == "clock" ]]
then
for clock in arm core h264 isp v3d uart pwm emmc pixel vec hdmi dpi
do
clockval=$(/opt/vc/bin/vcgencmd measure_clock $clock | awk -F"=" ‘{print $2}’)
echo "clock$clock.value $clockval"
done
fi
if [[ "$sensor" == "volt" ]]
then
for volt in core sdram_c sdram_i sdram_p
do
voltage=$(/opt/vc/bin/vcgencmd measure_volts $volt | awk -F"=" ‘{print $2}’ | tr -d "V")
echo "volt$volt.value $voltage"
done
fi
[/sourcecode]
I’ll post some sample screenshots in a bit!
I run a little ngIRCd server (well two) for some friends to use (if you’re a friend, and you want to know more, mail me!)
I’m also addicted to numbers, and I’m always interested in monitoring the stuff I run, so I’ve written (adapted really) an existing script to track how many users are connected to the ngIRCd daemons using munin.
I’m hosting them on github (along with some other stuff I wrote, or am writing). If you’re interested, you can check them out (hah, get it? I made a version control joke!) here.
I run a news server (using INN2), and I graph the performance of the server on which it sits using Munin. I used to use Cacti, but find Munin much, much easier to set up and get going, even if the interface isn’t quite as fancy.
Munin comes with a collection of regular plugins for graphing various linux services and system stats (such as Apache, MySQL, etc.) but it obviously can’t include everything. I spent about 10 minutes seeing if anyone had written their own plugin for reporting on INN2 traffic stats, but couldn’t see anything. So I rolled my own. I tried this under Cacti and frankly, it was painful. Not so much the script to gather the data, but getting the graphs actually up and running.
With Munin, it’s trivial. You can read all about it here, which is where I worked out what I needed to do.
Disclaimer: My shell scripting is shockingly lazy, and my use of awk can be compared to someone playing an exquisite 400 year old violin with a hammer. Sorry, but suck it up.
I use Munin on a Debian system installed, so the paths may vary depending on your setup. You need to complete three steps.
Munin collects data every 300 seconds. You need a script which can be run every 300 seconds to return data. The output of your script should be,
datavariable.value actualvalue
where datavariable is the name you give your erm, data variable, value is the word value and actualvalue is the value you want to graph. If you have several values, you just output them one line at a time,
datavariable.value actualvalue
datavariable_b.value actualvalue
datavariable_c.value actualvalue
Once you have a script which can output that, you’re most of the way there.
What Munin actually graphs is based on what your script outputs when it is passed a command line parameter of config. There are a bunch of values you should return which describe the graph, and then a bunch of values which describe the variables (i.e. the stuff above returned by your script), their format and how they should be put onto the graph. Here’s a simple example,
[sourcecode language=”bash” gutter=”false”]
echo ‘graph_title CPU usage’
echo ‘graph_vlabel %’
echo ‘graph_scale no’
echo ‘graph_info This graph shows how CPU time is spent.’
echo ‘system.label system’
echo ‘system.draw AREA’
echo ‘system.min 0’
[/sourcecode]
That would tell Munin to create a graph with the relevant title, to label the vertical axis with a single %, add a little bit of text and graph a single variable called system. The system variable is labelled on the graph as system, is an AREA plot and has a minimum value of 0.
There’s plenty more you can do, which you can read about on the Munin site, but that’s the basic stuff, and should be returned when your script is called with config on the command line. (By the way, your script can be anything executable, perl, shell, etc.)
You should place your script (executable) in /etc/munin/plugins or a link to it. You should also add various config options to /etc/munin/plugin-conf.d/munin-node which control how your script behaves. I’m not covering that in detail here but it’s fairly obvious.
You then restart the munin agent, and bingo your stuff turns up. Like magic.
So, if you want to graph INN2 data, set INN2 to output stats (inn.conf and innfeed.conf) every 300 seconds (or quicker). Then use the following two scripts, and entries in the munin-node config file (as appropriate for your installation).
[sourcecode language=”bash”]
#!/bin/sh
#
# Plugin to monitor inn2 status file, and report incoming traffic
#
# Require read permissions on the appropriate status file, and INN2 to be configured
# to update the file at or quicker than every 5 minutes.
#
#
#
# Parameters:
#
# config (required)
# autoconf (optional – used by munin-config)
#
# Magick markers (optional):
#%# family=auto
#%# capabilities=autoconf
#
# config example for /etc/munin/plugin-conf.d/munin-node
#[inn2_incoming]
#user news
#group news
#env.logfile /var/log/news/inn_status.html
#
LOG=${logfile:-/var/log/news/inn_status}
CATEGORY=${category:-inn2}
if [ "$1" = "autoconf" ]; then
if [ -r "$LOG" ]; then
echo yes
exit 0
else
echo no
exit 1
fi
fi
if [ "$1" = "config" ]; then
echo ‘graph_title INN2 incoming article stats’
echo ‘graph_args –base 1000 -l 0’
echo ‘graph_scale no’
echo ‘graph_vlabel article count’
echo ‘graph_category’ $CATEGORY
echo ‘graph_period minute’
echo ‘offered.label Total articles offered’
echo ‘offered.type DERIVE’
echo ‘offered.min 0’
echo ‘accepted.label Articles accepted’
echo ‘accepted.type DERIVE’
echo ‘accepted.min 0’
echo ‘refused.label Articles refused’
echo ‘refused.type DERIVE’
echo ‘refused.min 0’
echo ‘rejected.label Articles rejected’
echo ‘rejected.type DERIVE’
echo ‘rejected.min 0’
echo ‘dupe.label Duplicate articles’
echo ‘dupe.type DERIVE’
echo ‘dupe.min 0’
exit 0
fi
awk -v RS="" ‘/global/ {print $0}’ < $LOG | awk -v RS="" -F":" ‘{printf "offered.value %d\naccepted.value %d\nrefused.value %d\nrejected.value %d\ndupe.value %d\n",$5,$7,$10,$13,$16}’
[/sourcecode]
[sourcecode language=”bash”]
#!/bin/sh
#
# Plugin to monitor inn2 status file, and report outgoing traffic
#
# Require read permissions on the appropriate status file, and INN2 to be configured
# to update the file at or quicker than every 5 minutes.
#
#
#
# Parameters:
#
# config (required)
# autoconf (optional – used by munin-config)
#
# Magick markers (optional):
#%# family=auto
#%# capabilities=autoconf
#
# config example for /etc/munin/plugin-conf.d/munin-node
#[inn2_incoming]
#user news
#group news
#env.logfile /var/log/news/innfeed.status
#
LOG=${logfile:-/var/log/news/innfeed.status}
CATEGORY=${category:-inn2}
if [ "$1" = "autoconf" ]; then
if [ -r "$LOG" ]; then
echo yes
exit 0
else
echo no
exit 1
fi
fi
if [ "$1" = "config" ]; then
echo ‘graph_title INN2 outgoing article stats’
echo ‘graph_args –base 1000 -l 0’
echo ‘graph_scale no’
echo ‘graph_vlabel article count’
echo ‘graph_category’ $CATEGORY
echo ‘graph_period minute’
echo ‘offered.label Total articles offered’
echo ‘offered.type DERIVE’
echo ‘offered.min 0’
echo ‘accepted.label Articles accepted’
echo ‘accepted.type DERIVE’
echo ‘accepted.min 0’
echo ‘refused.label Articles refused’
echo ‘refused.type DERIVE’
echo ‘refused.min 0’
echo ‘rejected.label Articles rejected’
echo ‘rejected.type DERIVE’
echo ‘rejected.min 0’
echo ‘missing.label Missing articles’
echo ‘missing.type DERIVE’
echo ‘missing.min 0’
echo ‘deferred.label Deferred articles’
echo ‘deferred.type DERIVE’
echo ‘deferred.min 0’
exit 0
fi
awk -v RS="" ‘/global \(process\)/ {print $0}’ < $LOG | awk -v RS="" -F":" ‘{printf "offered.value %d\naccepted.value %d\nrefused.value %d\nrejected.value %d\nmissing.value %d\ndeferred.value %d\n",$5,$7,$9,$11,$13,$15}’
[/sourcecode]
Obviously, depending on your version of INN2, you may have to tweak the awk entry to get the right values.
Lastly, put the following lines into /etc/munin/plugin-conf.d/munin-node
[sourcecode language=”plain” gutter=”false”]
[inn2_incoming]
user news
group news
env.logfile /var/log/news/inn_status.html
[inn2_outgoing]
user news
group news
env.logfile /var/log/news/innfeed.status
[/sourcecode]
And again, those values will need to change to match your distribution / INN2 setup. Hope this helps someone.